This video tutorial covers the concepts of work and power, explaining how to calculate work done using force and distance, and how to calculate power using work and time. It includes examples such as lifting a rock and a weight lifter scenario to illustrate these calculations. The tutorial also demonstrates how to derive the mass of a barbell using power, distance, and time, emphasizing the importance of understanding the relationship between force, work, and power in physics.

What is the main topic of this video?

• Energy conservation

• Calculations in work and power

• Wind turbine mechanics

• Basic physics principles

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NGSS.HS-PS3-3

What is the formula for calculating work?

• Force divided by distance

• Force times distance

• Work divided by time

• Distance divided by force

What are the units of work?

• Joules

• Meters

• Newtons

• Watts

If a 50 newton rock is lifted 2.1 meters, how much work is done?

• 2.1 joules

• 50 joules

• 105 joules

• 105 watts

Tags

NGSS.HS-PS2-1

How is power calculated?

• Work times time

• Distance divided by force

• Force times distance

• Work divided by time

What is the power used if 105 joules of work is done in 5.8 seconds?

• 18.1 watts

• 105 watts

• 5.8 watts

• 50 watts

How much work is done when holding a 1500 newton barbell above the head for 5 seconds?

• 1500 joules

• 3000 joules

• 7500 joules

• 0 joules

Why is no work done when holding a weight stationary above the head?

• Because the force is zero

• Because the distance is zero

• Because the time is zero

• Because the weight is zero

If a weight lifter uses 2000 watts to lift a barbell 2 meters in 2 seconds, what is the work done?

• 8000 joules

• 4000 joules

• 2000 joules

• 1000 joules

Tags

NGSS.HS-PS3-1

What is the mass of a barbell if the weight is 2000 newtons and the acceleration due to gravity is 9.8 m/s²?

• 204 kg

• 200 kg

• 220 kg

• 180 kg

Tags

NGSS.HS-PS2-1